Rotary compressor unit



Filed Nov. 29, 1929 3 Sheets-Sheet i. um

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Oct. 25, 1932. E. F. HUBACKER ROTARY oMPREssoR UNIT Y Filed Nov. 29, 1929 5 sheets-sheet 5 Patented Oct. 25, 1932 UNITED STATES PATENT OFFICE EARL F. HUBACKER, OF DETROIT, MICHIGAN, ASSIGNOR TO NORGE CORPORATION, F v DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN Cri ROTARY COMPRESSOR UNIT Application led November 29, 1929. Serial No. 410,287.

This invention relates to an improved compressor unit adapted for use in domestic refri reration apparatus.

t is an object of this invention to provide an improved and simplified compressor of the rotary type direct connected to a driving motor, wherein unloading means are provided to facilitate starting up without a heavy current demand by the driving motor. l`o this end I provide a bypass from the dellvyery or high pressure side of the compressor to the suction or intake passages thereof, and suitably control this passage as by providing a centrifugal unloader valve adapted to close the passage after the motor picks up sufficient speed. When the valve is open the high pressure gas ls thus bypassed to the suction side of the compressor, so that no pumping load 1s imposed thereon since the high pressure gas simply circulates through the pump.

It is another object of this invention to provide an improved unit of the class described comprising a direct connected motor and compressor unit mounted in a closed casing with the driving shaft mounted vertically and having an aperture therethrough, the

lower shaft end being mounted on a combined seal ring and bearing which carries the weight of the shaft While affording sealed communication with the aperture therein.

It is a'further object of this invention to provide an 'improved rotary compressor structure of the double blade type wherein a cylinder is mounted concentrically relative to Va drivngshaft carrying an eccentric rotor therein. The rotor or eccentric is provided with a oating sleeve adapted to make rolling contact with the cylinder and blade, one end seal being pinned in position to overlap both the cylinder and sleeve ends, so that gthe s ealv is held while being yielchng' in an axial to relieve excesslvepressums within the compresor.

It 'u l. fdl-ther object of this invention to provide an improved rotary compressor of the multiple blade type wherein the movement of the rotor serves as l. valve controlling st lction ports, thus eliminating the need of 1ndividunl suction valves; a single check or non-return valve being provided in the suction line to prevent back flow of high pressure gas when the compressor is shut down.

Other and further important objects of this invention will be apparent fromthe disclo# sures in the specification and the accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawings:

Figure l is a vertical section through a compressor unit embodying the preferred form of this invention.

Figure 2 is a section on the line lI-II of Figure l shoiving lthe cylinder With the Suction port locations in lthe base.

Figure 3 is a section on the line IIL-Ill of Figure 1 showing the cylinder with the discharge valve locations in the cover.

Figure 4 is a section on the line IV-IV of Figure 1 showing a plan view of the cylinder cover.

Figure 5 is a section on the same line as Figure 3 but taken in the opposite direction.

'As shown on the drawings:

The compressor and motorunit is intended to be mounted in a sealed casing comprising an inverted cuplike member 10, having cooling fins 11y appliedthereto, which is closed Yshaft and serves to carry the weight of the rotating parts associated with the shaft, this seal ring bearing against a Cover 19 bolted to the bottom face of the closure 12. The

seal ring also serves to prevent leakage between the shaft passage 17 and the spaces on the suction side of the compressor hereinafter toY be described.

A compressor base plate 20 is mounted on the inside surface of the casing closure 12l and a compressor cylinder vf2.1 is in turn mounted thereon, the cylinder and base plate being aligned and clamped down by a saddle-like enveloping membel` 22 having a central upstanding boss 23 forming an upper guide bearing 24 for the shaft 16. The upper end of the boss 23 is dished as at 25 about the bearing 24 to form an oil collecting pocket.

The projecting upper end of the shaft carries a motor armature 26 the field and winding 27 therefor being mounted on a ring 28 supported by upwardly extending arms 29 from the saddle-like member 22. The armature 26 is clamped against a shoulder on the shaft 16 by a nut 30 which is provided with oppositely' disposed pivots 31 supporting weighted arms 32 which engage a collar 33 in turn engaging a valve stem 34 mounted in the shaft aperture 17 and cooperating with a valve seat 35 therein. This assembly forms a centrifugal unloading valve which is opened by the weighted arms 32 below a predetermined rotative speed but is closed by the outward swing of the weighted ends of the arms 32 under the influence of centrifugal force; the action of the arms being similar to that of a iiyball governor.

When this unloader valve is open vit admits high pressure gas, from the upper part of the casing, into the shaft passage 17 and through the bottom seal ring 18 from where a passage 36 leads to a check valve chamber 37 in the cover 19. This check valve chamber has an anteriorly disposed inlet passage' 38 containing a screen 39 which passage forms the suction connection to the freezer or evaporator unit of a refrigerating system. A valve seat 40 is interposed between the inlet passage 38 and the chamber 37, a disc valve 41 seating thereagainst to prevent back How of high pressure gas into the suction line. This disc valve is held on its seat by a light spring 42 on a spring guide 43 clamped bet-Ween the closure 12 and the cover 19. From the check valve chamber 37 a passage 44 leads to a crescent shaped groove 45 in the closure 12 immediately below the compressor base plate 20, which base plate contains diametrically disposed suction ports 46 opening into the compressor cylinder on the suction sides of partition blades 47 which reciprocate. in slots in the cylinder walls. These Vblades carry outwardly projecting stems 48 on which v53 formed on the shaft 16.

spring seats 49 are mounted, springs 50 held by brackets 51 acting thereagainst to urge the blades inwardly.

The inner ends of the blades 47 ride on an eccentric floating sleeve 52 which is oscillated around within the cylinder by an eccentric The loscillating movement of the floating sleeve 52 uncovers the suction ports 46 at the proper time inthe cycle of operationso that suction valves are unnecessary. .l

tween which thin steel iapper valves 56 are caught, these valves controlling discharge ports 57 throughthe plates to prevent backfloW of high pressure gas into' the compressor. The plates 54 and 55 are pinned at 58 against rotation but are free to lift upon the generation of excessive pressures wi-thin the compressor.

Lubrication of the working parts is provided by an oil bath submerging the compressor and subjected to the discharge pressure thereof which causes sufficient quantities of oil to work 1n past themoving surfaces into the suction regions of the compressor to efficiently lubr1cate the same. In order that the compressor may discharge above the oil level, bosses 59 are formed on the top plate about the discharge ports 57, and one of these bosses is provided with a tube 60 leading the discharge into the oil trap 25 formed above the shaft bearing 24, so that oil entrained in the compressor discharge is deposited in the trap and serves to maintain lubrication at this point. The lower shaft bearing is lubricated by a groove 61 and a direct passage 62 in the bottom closure 12, below the oil level 'in the casing.

For high speed operation it is desirable to balance the rotating parts, to which end a counterweight 63 is applied to the shaft to balance the weight of the eccentric thereon.

The operation is as follows:

The compressor eccentric 53 rotates clockwise in Figure 2 so that the lower portion of vthe crescent shaped space between the floating sleeve 52 and the cylinder wall is increasing in volume, drawing in low pressure gas through the .right hand suction port 46. At the same time the part of the crescent shaped space above the partition blades is decreasing in volume thus compressing the gas therein which is discharged through the lright hand discharge port 57 and valve 56 in Figure 3. As Figure 3 is an upside down view, the direction of rotation and the upper and lower compression spaces are reversed relative to Figure 2. This simultaneous compression and suction on opposite sides of the partition blades gives two delivery strokes per revolution of the eccentric. Since the sleeve is free on the eccentric its motion is largely a rolling one within the cylinder because the continuous bearing surface between the sleeve and the 'eccentric offers much less friction than the line contact between the sleeve and the cylinder and partition blades. A

The cover plates 54 and 55 are held down onto the cylinder and sleeve by the high pressure gas in the upper part of the casing, thus forming a releasable end seal which can yield under excessive Ilpressures as when a slug of liquid works into the compressor.

In order to facilitate starting of the compressor and m'otor unit the compressor is relieved of its load and thus the heavy starting current demand by the motor is materially reduced. This result is accomplished by the centrifugal unloading valve, which bypasses high pressure gas to the suction an improved and simplilied compressor unit wherein suction ports replace the usual valves; wherein excessive pressures can be met without damage to the compressor; and wherein the starting load is materially reduced. I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the vprinciples of this invention, and I therefore do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

l. A device of the class described comprising a closed casing, a rotary comp-ressor, a driving shaft therefor and a driving motor mounted on said shaft, the compressor, shaft` and motor being enclosed in said casing, a relief passage extending aX-ially through said shaft, a centrifugal'unloading valve controlling said relief passage, a suction supply passage to said compressor having a branch in communication with the relief passage in said shaft, and a check valve in said suction supply passage and anteriorly located relative to said branch.

2. A device of the class described comprising a closed casing, a rotary compressor, a driving shaft therefor and a driving motor mounted on said shaft, the compressor, shaft and motor being enclosed in said casing, a

relief passage extending axially through said shaft, a centrifugal unloading valve controlling said relief passage, a suction supply passage to said compressor having a branch in communication with the relief passage in said shaft, a combined seal ring and bearing support at the end of said shaft to prevent leakage from said relief passage adjacent they 'suction branch, and a check valve in said suction supply passage and anteriorly located relative to said branch.

3. A device of the class described com rising a closed casing containing a bath o lubricant, a rotary compressorsubmerged in said bath of lubricant, a driving shaft therefor and a driving motor mounted on said shaft, the compressor, shaft and motor being enclosed in said casing, a relief passage extending axially through said shaft, a centrifugal unloading valve controlling said relief passage, a suction supply passage to said compressor having abranch in communication.

with the relief passage in said shaft, and a check valve in said suction suppl assage and anteriorly located relative to said ranch.

4. A device of the class described comprising a closed casing containing a bath of lubricant, a rotary compressor submerged in said bath of lubricant, a driving shaft therefor and a driving motor mounted on said shaft, the compressor, shaft and motor being enclosed in said casing, a relief passage extending axially through said shaft, a centrifiigal unloading valve controlling said relief passage, a suction supply passage to said compressor having a branch in communication with thev relief passage in said shaft, a combined sealring and bearing support at the end of said shaft to prevent leakage from said relief passage adjacent the suction branch, and a check valve in said suction supply passage and anteriorly located relative to said branch.

5. A device of the class described comprising a closed casing having a removable bottom closure, a hollow shaft vertically journalled in said bottom closure, a seal ring and thrust bearing supporting said shaft, an eccentric carried by said shaft, a rotary compressor operated by said eccentric, discharge outlets from said compressor opening into the casing, a suction inlet passage in said bottom closure leading to said compressor, a branch passage therefrom communicating with the interior of said hollow shaft through the seal ring, and a centrifugal unloading valve controlling the admission of Huid to the interior of the hollow shaft at the upper end thereof.

6. A device of the class described comprising a closed casing` having a removable bottom closure, a hollow shaft vertically journalled in said bottom closure, a seal ring and thrust .bearing supporting said shaft, an eccentric carried by said shaft, a rotary compressor operated by said eccentric, discharge outlets from said compressor opening into the casing, a suction inlet passage in said bottom closure leading to said compressor, a branch passage therefrom communicating with the interior of said hollow shaft through the seal ring, a check valve in said suction passage anterior to the branch passage, and a centrifugal unloading valve controlling the admission of fluid to the interior of the hollow shaft at the upper end thereof.

7. A device of the class described comprising a closed casing having a removable bottom closure, a hollow 'shaft vertically journalled in said bottom closure` driving means engaging the upper portion of said shaft, an eccentric' carried by said shaft, a rotary compressor operatedby said eccentric, discharge outlets from said compressor opening into thecasing, a suction inlet passage in said bottom closure leading to said compressor, a branch passage therefrom communicating with the interior of said hollow shaft, and a centrifugal unloading valve controlling the admission of fluid to the interior of the hollow shaft at the upper end thereof.

8. A device of the class described comprising a closed casing having a removable. bottom closure, a hollowl shaft vertically ]ournalled in said bottom closure, driving means engaging the upper portion of said shaft, an eccentric carried by said saft, a rotary comm pressor operated by said eccentric, discharge outlets from said compressor opening into the casing, a suction inlet passage in said bottom closure leading to said compressor, a branch passage threrefrom communicating with the interior of said hollow shaft, a check valve in said suction passage anterior to the branch passage, and a centrifugal unloading valve controlling the admission of fluid to the interior of the hollow shaft at the upper end thereof.

9. A compressor ofl the class describedl comprising a casing having a removable closure, a compressor base plate thereon, a shaft journalled in said closure, an eccentric 2lil on said shaft, a. sleeve floating on said eccentric, a cylinder on said base plate inclosing said sleeve and eccentric, suction ports through said casing closure and base plate, a closure for the other end of saidv cylinder, 80 mounting means therefor adapted to prevent rotation thereof while permitting movement Iin `alignment with the shaft, and compressor discharge means 'in said cylinder closure.

10. A compressor of the class described 85 comprising a casing having a removable closure, a compressor base plate thereon, a shaft journalled in said closure, aneccentric on said shaft, a sleeve floating on said eccentric', a cylinder on said base plate inclosing said sleeve and eccentric, suction ports through said casing closure and base plate,

a closure for the other end of said cylinder, mounting means Vtherefor adapted to ,prevent rotation thereof while permitting 4s-movement in alignment with the shaft,

compressor discharge means in said cylinder closure, and a conduit connected to said discharge means to conduct said discharge toa osition adjacent said shaft for lubricating t esame.

1 11. A compressor of the class described comprising a casing having a removable closure, a compressor base plate thereon, a shaft journalled in said closure, an eccentric on said shaft, a sleeve floating on said eccentric, a cylinder on said base plate enclosing said sleeve and eccentric; suction ports through said casing olo'suredand base plate, a closure for the Other-end of said cylinder, mounting means therefor adapted to prevent rotation thereof whilev permitting movement in alignment vwith the shaft, compressor discharge means in said cylinder closure, a relief passage formed in said shaft and communicating with the compressor suction ports, and an automatic unloading valve controlling said relief assage.

12. compressor of the class described comprising a casing having a removable closure, a compressor base plate thereon, a ,70 shaft journalled in said closure, an eccentric on said shaft, a sleeve floating on said eccentric, a cylinder on said base plate enclosing said sleeve and eccentric, suction ports through said casing closure and base plate, a closure for the other end of said cylinder, mounting means therefor `adapted to prevent rotation thereof while permitting movement in alignment with the saft, compressor discharge means in said cylinder closure, a conduit connected to said discharge meansy to conduct said discharge to a position adjacent said shaft for lubricating the same, a relief passage formed in said shaft and communieating with the compressor suction ports, and an automatlc unloading valve controlling said relief passage.

13. A compressor of the class described comprising a base plate having suction ports therein, a cylinder mounted lon said base plate, a shaft centrally mounted relative to said cylinder, an eccentric on said shaft, a sleeve mounted on said eccentric-and cooperating wif--h said cylinder, an end cover for said cylinder, means restraining the cover from rotation While permitting longitudinal movement under excessive pressures in the cylinder, and discharge ports and valves in said cover.

14. A compressor of the class described comprising a base plate having suction ports therein, a cylinder mounted on said base plate, a shaft centrally mounted relative to said cylinder, an eccentric on said shaft, a sleeve mounted on said eccentric and cooperating with said cylinder, an end cover for said cylinder, cans restraining the cover from rotation iile permitting longitudinal movement under excessive pressures in the cylinder, discharge ports and valves in said cover, and a conduit connected to said discharge means to conduct said discharge to a positionadjac'ent said shaft for lubricating Ithe same.

I 15. A compressor of the class described. comprising a base plate having suction ports therein, a cylinder mounted on said base plate, a shaft centrally-mounted relative to vsaid cylinder, an eccentric 4on said shaft, a

sleeve mounted on said eccentric and cooperating with said cylinder, an end cover for said cylinder, means restrainingthe cover from rotation whilevpermitting longitudinal movement under excessive pressures in the cylinder, discharge ports and valves in said cover, a reliefpassage formed in said shaft and communicating with vthe compressor suction ports, and an automatic unloading'valve controllmg said relief passage.

16. A compressor of the class described 13 com risin a base plate havin' g suction ortstherlein, age linder mounted on saidpbase plate, a sha centrally mounted relative to said cylinder,.an eccentric on said shaft, a 5 sleeve mounted on said eccentric and cooperating with said cylinder, artition members slidablyv mounted in sai cylinder walls, means adapted to maintainv said partition members in vcontact with said sleeve, an end I". cover for said cylinder, means restraining the cover from rotation while permitting longitudinal movement under excessive pressures in the cylinder, discharge ports and valves in said-cover, and a conduit connected to said discharge'means to conduct said discharge to a osition adjacent said shaft for lubricatingt e same. l 17. A compressor of the class described vcomprising a base plate having suction ports 20 therein, a cylinder mounted on said base plate, a shaft centrally mounted relative to said cylinder, an eccentric on said shaft, a sleeve mounted on said eccentric and4 cooperatin with said cylinder2 partition mem- 25 bers shdably mounted inv sald cylinder walls, means adapted to maintain said partition members in contact with said sleeve, an end cover for said cylinder, means restraining the cover from rotation while permitting lon 3u gitudiual movement under 'excessive pres- A sures in the cylinder, discharge ports and valves in said cover, a relief passage formed in said .shaft and communicating with theV compressor suction ports, and an automatic 35 unloading valve controlling said relief passa es. testimony whereof I have hereunto subscribed my name at Detroit, Wayne County,

Michigan.4 'l

' EARL F. HUBACKER. 

